Papers - SUZUKI Yoshihiro
-
Suzuki Y., Takabayashi T., Kawaguchi T., Matsunaga K.
Journal of Experimental Marine Biology and Ecology 225 ( 1 ) 69 - 77 1998.7
Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Experimental Marine Biology and Ecology
An allelopathic substance that destroys zoospores of the brown alga, Laminaria religiosa Miyabe, was isolated by several separation techniques from the ethanol extract of the crustose coralline alga, Lithophyllum spp. A bioassay was used to test the effect of isolated fractions against the dinoflagellate, Heterosigma akashiwo Hada, and zoospores of L. religiosa. Further purification of the allelopathic substance in ether phase by silica gel column chromatography revealed that the isolated active substance had major absorption peaks at 220, 263 and 283 nm in the UV region and exhibited characteristics consistent with a nonpolar group. The results suggest that allelopathy may play an important role for reducing epiphyte growth on crustose coralline algal surfaces and may partially explain their predominance in the coastal region of the northern Japan Sea.
-
MARUYAMA Toshiroh, SUZUKI Yoshihiro, KAWAZOE Satoshi, DOTE Yutaka, MASUDA Sumio
Journal of Japan Society on Water Environment 21 ( 5 ) 310 - 317 1998.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society on Water Environment
Red tide outbreaks kill great number of cultured fish resulting in the serious problem for fisheries. In this study, to clarify the ability of the foam-separation system for collection of red tide plankton, the optimum conditions of this system was investigated by batch system.The results are as follows : (1) It was clear that the foam-separating system was very effective for collecting plankton by combined use of a coagulant (poly ferric sulfate : PFS) and protein (casein). When added PFS and casein at dosage of 40mg-Fe·l-1 and 15mg·l-1, respectively, the recovery of Heterosigma akashiwo, Chattonella antiqua and Gymnodinum mikimotoi were 99%, and the ratio of volume of foam waste water to total amount of red tide seawater was about eight percent. The optimum dosages of PFS and casein for collecting diatom (Pheaodactylum tricornutum, Skeletonema costatum, Chaetoceros sociale) and H. akashiwo were less than that for above two red tide species.(2) Approximately 100% of dosed PFS and casein were recovered from the treated seawater. Furthermore, about 99% of phosphate was removed from the red tide seawater by coagulation.(3) AGP tests showed that the growth of red tide plankton (H. akashiwo, C. antiqua and G. mikimotoi) were strongly limited in the treated seawater.
DOI： 10.2965/jswe.21.310
-
The effect of fulvic acid-Fe derived from the forest on the growth of Laminaria religiosa Miyabe and Undaria pinnatifida Suringan Reviewed
K. Matsunaga, G. Nigi, Y. Suzuki, H. Yasui, G. Deein
Bulletin of Society Sea Water Science, Japan 52 ( 5 ) 315 - 318 1998.5
Language：English Publishing type：Research paper (scientific journal)
-
MARUYAMA Toshiroh, SUZUKI Yoshihiro
NSUGAF 64 ( 2 ) 216 - 226 1998.3
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Japanese Society of Fisheries Science
-
Maruyama T., Suzuki Y.
Nippon Suisan Gakkaishi (Japanese Edition) 64 ( 2 ) 216 - 226 1998.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Nippon Suisan Gakkaishi (Japanese Edition)
-
Effect of Biomass Measurements on Toxicity Evaluation in Algal Growth Inhibition Tests.
SUZUKI Yoshihiro, MORISHITA Reiko, TAKAMI Tohru, MARUYAMA Toshiroh
Doboku Gakkai Ronbunshuu G 35 101 - 109 1998
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
General methods for the biomass measurements in algal growth inhibition tests are cell counting, absorbance, and fluorescence, but a standard method is not restricted by the standard procedures. The possibilityof the different evaluation is present in the toxicity test by different biomass determinations.In this study, the toxicity of copper (Cu) and monochloramine (NH<SUB>2</SUB>Cl) as reference toxic substances wereevaluated from the algal growth inhibition test using green alga Selenasturum capricornutum. To determine thebiomass changes, direct cell counting, turbidity, chlorophyll with fluorescence, and ATP methods were used andthe effective concentration of Cu and NH<SUB>2</SUB>Cl were evaluated with each results. The most sensitive method of theevaluation was direct cell counting, then LOEC and EC<SUB>50</SUB> of Cu were 10 and 7 μg/l, and LOEC and EC<SUB>50</SUB> of NH<SUB>2</SUB>Cl were 7 and 19 μg-Cl<SUB>2</SUB>/l, respectively. Turbidity and fluorescence methods showed the same sensitivity for Cu, whereas these were not sensitive for NH<SUB>2</SUB>Cl. In contrast, the sensitivity of ATP method was not good for bothtoxic substances, and the evaluated values of LOEC and EC<SUB>50</SUB> with ATP were several times higher than withcounting method. It is necessary to recognize that the method for biomass measurements in algal growth test hasan effect on the estimation.
-
Effect of Nutrients Condition on a Toxicity Evaluation of Monochloramine by Algal Growth Test Reviewed
SUZUKI Yoshihiro, MORISHITA Reiko, MARUYAMA Toshiroh
Journal of Japan Society on Water Environment 20 ( 11 ) 783 - 788 1997.11
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society on Water Environment
The toxicity of monochloramine (NH2Cl), which is the main by-product of sewage effluent chlorination, was evaluated from growth inhibition in different condition of nutrients by a green alga Selenastrum capricornutum. The effect of NH2C1 on algal growth was depended on the nutrients condition, and nutrients limited algal cells were more sensitive than the non-limited cells. When using the nutrient-limited algal cells for the test organisms, lowest-observed-effect concentration (LOEC) and 50% effective concentration (EC50) after 96 hours exposed period were 0.001 and 0.002 mg-Cl2·l-1, respectively.The obtained LOEC and EC50 were lower than the water quality criteria for residual oxidants and the detection limit of oxidant determination. It is clear that chemical analysis is insufficient to monitor the various effluents. From these results, an algal growth test using the nutrient-limited algal cells is very sensitive and useful for the toxicity evaluation of disinfected effluents.
DOI： 10.2965/jswe.20.783
-
河口域に位置する屎尿処理場の操業開始と操業停止に伴う河口・沿岸域の底質変化およびヒロハノヒトエグサ養殖の収穫変動 Reviewed
三浦昭雄，丸山俊朗，鈴木祥広
用水と廃水 39 ( 6 ) 15 - 21 1997.6
Language：Japanese Publishing type：Research paper (scientific journal)
-
TOXICITY TESTING USING CONCHOSPORES AND THEIR GERMLINGS OF PORPHYRA YEZOENSIS Reviewed
TAKAMI Tohru, MARUYAMA Toshiro, SUZUKI Yoshihiro, MIURA Akio
566 71 - 80 1997.5
Language：Japanese Publishing type：Research paper (scientific journal)
-
SUZUKI Yoshihiro, MARUYAMA Toshiro, MIURA Akio, SHIN Jong-ahm
559 73 - 79 1997.2
Language：Japanese Publishing type：Research paper (scientific journal)
-
Toxicity Testing Using Conchospores and Their Germlings of Porphyra Yezoensis.
Takami Tohru, Maruyama Toshiro, Suzuki Yoshihiro, Miura Akio
Doboku Gakkai Ronbunshu 1997 ( 566 ) 71 - 80 1997
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
The objective of this study is to establish the methodology of toxicity test of detrimental substances using conchospores and their germlings of <i>Porphyra yezoensis</i>. Release of conchospores from mature free-living conchocelis took place after 7 days when the culture transfered from 23°C to 15°C temperature conditions with 10hL:14hD in 1/20PES medium, and 80% of conchospores were released for first 3 hours when the light condition was changed from off to on in a day. As substrata to be adhered conchospores, the glass plate was the most adequate and concerning the method of adhering conchospores, natural sedimentation of conchospores onto the glass plate was the most adequate. Adhesion and survival ratios of conchospores were constant, even if the date and the number of collecting conchospores were different.
-
Effect of Suspended Matters on the Adhesion of Porphyra Yezoensis Conchospores. Reviewed
Suzuki Yoshihiro, Maruyama Toshiroh, Miura Akio
Doboku Gakkai Ronbunshu 1997 ( 580 ) 19 - 26 1997
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
The effect of different kinds of suspended matters and their grain size on the adhesion onto the substrate of <i>Porphyra yezoensis</i> conchospores were investigated. The results are summarized as follows: (1) The inhibition effect of the adhesion of conchospores were depended on the size of the suspended clays, and the large particles were more effective in the inhibition than the small ones at the same concentration. (2) Five kinds of clay inhibited adhesion of conchospores in their low concentration. (3) The suspended organic matters had the smaller influence on the adhesion of conchospores than the clay particles.
-
Suzuki Yoshihiro, Maruyama Toshiro, Miura Akio, Shin Jong-ahm
Doboku Gakkai Ronbunshu 1997 ( 559 ) 73 - 79 1997
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers
Effects of suspended or accumulated kaolinite particles on the adhesion and the germination of <i>Porphyra yezoensis</i> conchospores were investigated under three types of condition; 1) suspended of conchospores with particles together, 2) accumulated of particles on the substrate before conchospores adhesion, and 3) accumulated of particles on adhered conchospores. Condition-1 was the most effective, and the 50% of effective concentration (EC<sub>50</sub>) was 3μg/cm<sup>2</sup>. When condition-2, it was difficult for conchospores to germinate even though 1μg/cm<sup>2</sup> of kaolinite particles. We may, therefore, reasonably conclude that the damages of seaweed community result from generation of suspended matters by human being's developmental activities in the coastal region.
-
Production of Monochloramine and Its Disappearance in Sewage Effluents by Chlorination Reviewed
SUZUKI Yoshihiro, MARUYAMA Toshiro, TAKAMI Tohru
Journal of Japan Sewage Works Association. Research journal 33 ( 407 ) 93 - 103 1996.12
Language：Japanese Publishing type：Research paper (scientific journal)
-
SUZUKI Yoshihiro, MORISHITA Reiko, MARUYAMA Toshiro
Journal of Japan Society on Water Environment 19 ( 11 ) 861 - 870 1996.11
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society on Water Environment
Monochloramine (NH2Cl) which is a highly toxic pollutant is usually contained in chlorinated sewage effluents. Effects of NH2Cl and chlorinated sewage effluent on freshwater ecosystem were investigated by an algal growth test using a green alga Selenastrum capricornutum.Toxicity of NH2Cl for the alga was stronger than that of free chlorine, and NH2Cl was extremely stable in freshwater. Lowest-observed-effect concentration (LOEC) of NH2Cl after 96 hours exposure was 0.01 mg-Cl2l-1. Comparison of chlorinated effluents with non-chlorinated effluents, the algal growth was inhibited significantly in chlorinated effluents. The final chlorinated effluents collected from the sewage treatment plant also affected the growth of alga, and about 80% of total residual oxidants in the effluents was detected as NH2Cl. On the contrary, the algal growth was not inhibited in dechlorinated effuents with Na2SO3 because of disappearance of the residual oxidant. Judging from these results, it was clear that NH2Cl was the most important pollutant in chlorinated wastewater effluents for aquatic organisms.
DOI： 10.2965/jswe.19.861
-
粉砕セメント固化体中有害重金属の低pH溶液への溶出に関する研究
土手 裕, 丸山 俊朗, 鈴木 祥広, 福嶋 知幸, 笹井 剛
廃棄物学会研究発表会講演論文集 = Proceedings of the Annual Conference of the Japan Society of Waste Management Experts 7 ( 2 ) 924 - 926 1996.9
Language：Japanese Publishing type：Research paper (scientific journal)
-
Disappearance of Monochloramine and Production of Residual Oxidant in Seawater Reviewed
SUZUKI Yoshihiro, MARUYAMA Toshiro, TAKAMI Tohru, DOTE Yutaka
Journal of Japan Society on Water Environment 19 ( 5 ) 388 - 396 1996.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society on Water Environment
Monochloramine (NH2Cl) is the strongest toxic substance resulting from chlorinated sewage effluent. To estimate of NH2Cl on the growth of organisms in coastal region, disappearance of NH2Cl in seawater was investigated.Changes concentration of NH2Cl and total oxidant in artificial seawater were determined. The concentration of NH2Cl decreased with time and reached to 20% of the initial concentration after 6 hour at 30°C. On the other hand, 90% of the initial concentration of total oxidant was detected after disappearance of NH2Cl. The rate constant of NH2Cl disappearance was not concerned in the initial concentration at constant temperature. Disappearance of NH2Cl depended on water temperature, and the rate constant followed the Arrhenius equation. The rate constant and half-life value at 20°C for NH2Cl in seawater were 0.031 h-1 and 10 h. These results suggested that the effluent contained NH2Cl would be enough to effect on coastal organism until its disappearance. NH2Cl disappearance depended on salinity. However, NH2Cl in artificial seawater without KBr was stable even in the same condition. It was clear that the disappearance factor of NH2Cl was in existence of Br-. NH2Cl changed to the other oxidant with Br-, therefore, the product which may act on organisms still remained in seawater after disappearance of NH2Cl.
DOI： 10.2965/jswe.19.388
-
土手 裕, 丸山 俊朗, 鈴木 祥広, 福嶋 知幸
廃棄物学会研究発表会講演論文集 = Proceedings of the Annual Conference of the Japan Society of Waste Management Experts 6 ( 1 ) 441 - 443 1995.10
Language：Japanese Publishing type：Research paper (scientific journal)
-
Bioavailable iron species in seawater measured by macroalga (Laminaria japonica) uptake Reviewed
共著者：Y. Suzuki, K. Kuma, K. Matsunaga
Marine Biology 123 ( 1 ) 173 - 178 1995.7
Language：English Publishing type：Research paper (scientific journal)
-
Iron requirement of brown macroalgae (Lamianria japonica, Undaria pinnatifida; Phaeophyta) and crustose coralline alga (Lithphyllum yessoense; Rhodophyta), and their competition in the northern Japan Sea Reviewed
Y. Suzuki, K. Kuma, I. Kudo, K. Matsunaga
Phycologia 34 ( 3 ) 201 - 205 1995.3
Language：English Publishing type：Research paper (scientific journal)